There are two ways in which you can access your cPanel account. Let us see these two ways,
Using your domain:
a. Proceed to your domain.com/cpanel
b. Log in using your cPanel username and password.
Using customer portal:
a. Proceed to the address: https://customers.hivium.com/clientarea.php?action=services
b. You will see all your active services with us.
c. Click on the service you want to log in to (if you have multiple services with us, select the appropriate one).
d. Now Click on the "Login to cPanel" option in the left-hand side menu.
If you still face any problems, please open a ticket with us.